HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 279, Issue 45, 47076-47080, November 5, 2004

This Article Full Text Full Text (PDF) All Versions of this Article: 279/45/47076    most recent C400417200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Enkvetchakul, D. Articles by Nichols, C. G. Search for Related Content PubMed PubMed Citation Articles by Enkvetchakul, D. Articles by Nichols, C. G. Social Bookmarking                      What's this?

Functional Characterization of a Prokaryotic Kir Channel^*

Decha Enkvetchakul, Jaya Bhattacharyya¶, Iana Jeliazkova¶, Darcy K. Groesbeck¶, Catherine A. Cukras¶, and Colin G. Nichols¶||

From the ^¶Department of Cell Biology and Physiology, and Division of Renal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110

The Kir gene family encodes inward rectifying K⁺ (Kir) channels that are widespread and critical regulators of excitability in eukaryotic cells. A related gene family (KirBac) has recently been identified in prokaryotes. While a crystal structure of one member, Kir-Bac1.1, has been solved, there has been no functional characterization of any KirBac gene products. Here we present functional characterization of KirBac1.1 reconstituted in liposomes. Utilizing a ⁸⁶Rb⁺ uptake assay, we demonstrate that KirBac1.1 generates a K⁺-selective permeation path that is inhibited by extraliposomal Ba²⁺ and Ca²⁺ ions. In contrast to KcsA (an acid-activated bacterial potassium channel), KirBac1.1 is inhibited by extraliposomal acid (pK_a 6). This characterization of KirBac1.1 activity now paves the way for further correlation of structure and function in this model Kir channel.

Received for publication, September 9, 2004 , and in revised form, September 23, 2004.

^* This work was supported by National Institutes of Health Grant HL54171 (to C. G. N.) and Clinician-Scientist Award DK60086 (to D. E.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

These authors contributed equally to this work.

^|| To whom all correspondence and reprint requests should be addressed. Tel.: 314-362-6630; Fax: 314-362-7463; E-mail: cnichols{at}cellbio.wustl.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				D. Enkvetchakul, I. Jeliazkova, J. Bhattacharyya, and C. G. Nichols Control of Inward Rectifier K Channel Activity by Lipid Tethering of Cytoplasmic Domains J. Gen. Physiol., August 27, 2007; 130(3): 329 - 334. [Abstract] [Full Text] [PDF]

				M. M.-C. Kuo, Y. Saimi, C. Kung, and S. Choe Patch Clamp and Phenotypic Analyses of a Prokaryotic Cyclic Nucleotide-gated K+ Channel Using Escherichia coli as a Host J. Biol. Chem., August 17, 2007; 282(33): 24294 - 24301. [Abstract] [Full Text] [PDF]

				L. Gao, X. Mi, V. Paajanen, K. Wang, and Z. Fan From the Cover: Activation-coupled inactivation in the bacterial potassium channel KcsA PNAS, December 6, 2005; 102(49): 17630 - 17635. [Abstract] [Full Text] [PDF]

				D. Enkvetchakul, I. Jeliazkova, and C. G. Nichols Direct Modulation of Kir Channel Gating by Membrane Phosphatidylinositol 4,5-Bisphosphate J. Biol. Chem., October 28, 2005; 280(43): 35785 - 35788. [Abstract] [Full Text] [PDF]

				S. H. Loukin, M. M.-C. Kuo, X.-L. Zhou, W. J. Haynes, C. Kung, and Y. Saimi Microbial K+ Channels J. Gen. Physiol., May 31, 2005; 125(6): 521 - 527. [Full Text] [PDF]